id	summary	reporter	owner	description	type	status	component	version	resolution	keywords	cc	guest	host
18560	Guest Windows hangs on startup with guest additions installed	iakovk		"Host: Windows 10 1803 prof
Guest: Windows 7 x86 prof

Today I found that my old VM hangs on startup: black screen with ""Starting Windows"" message.
It doesn't connect to debugger (the debugging was turned on in the guest etc; in previous version of VirtualBox it worked).
I reinstalled Windows fresh in the guest.
It worked normally for a while.
I installed Guest Additions, rebooted and it hung.
Log file contains nothing interesting. The last message is:
00:05:11.555304 GUI: UIFrameBufferPrivate::performResize: Size=1024x768, Directly using source bitmap content
"	defect	new	other	VirtualBox 6.0.4				Windows	Windows